Garage door won't close

Often, a door that will not close is doing what the law requires of it. Every residential opener made for sale in the United States since January 1, 1993 has had to carry a second layer of protection against closing on someone, and on most openers that layer is a pair of photo-eye sensors near the floor. When the beam between them is blocked or the two sensors no longer face each other, the opener refuses to bring the door down.

Check the sensors first

This part is yours, and the opener's maker says so.

• Find the two small sensors on either side of the door opening, a few inches off the floor. The federal safety agency's guidance is that an electric eye "should be installed at a height of 4 to 6 inches above the floor" (CPSC Pub. 523).
• Clear the beam. A bin, a bag, a leaf or a cobweb across the path is enough.
• Wipe both lenses.
• Look at the indicator lights. On many openers a steady light on each sensor means they see each other; an off or blinking light means they do not. If one was knocked out of line, the manufacturer's support pages walk owners through lining them back up (Chamberlain support).

If the door closes only while you hold the wall button down, the opener is behaving as though the sensors are blocked. Holding the button can shut the garage tonight, but only if you keep the door in sight the whole way down and nobody crosses under it. The federal text in every residential opener's manual says: "Always keep the moving door in sight and away from people and objects until it is completely closed." It is not a repair, and with the sensors out, the person holding the button is the only protection.

The door reaches the floor and goes back up

The rule for residential openers is that a closing door must start to reverse "within 2 seconds of contact with the obstruction" (16 CFR 1211.7(b)(1)(i)). An opener that treats the floor itself as an obstruction has limit or force settings that no longer match the door. The manual gives the adjustment, and the same federal text requires a retest afterward: "After adjusting either the force or the limit of travel, retest the door opener." If it then fails the 2-by-4 test, stop using it and call. If the door also feels heavy, hangs unevenly or has started making new noises, the settings are not the real problem: see broken spring and snapped cable.

The door stops partway down and won't go further

A door that jams, tilts or grinds on the way down has a problem in the door, not the opener. See off track. The Consumer Product Safety Commission's advice for a door that binds or sticks is that it "should be serviced by a professional" (CPSC Pub. 523).

Never disconnect the sensors

It can be tempting to unplug a sensor or tape them together so the door will close. The federal rule requires a residential opener to have a second means of protection beyond the reversal on contact (16 CFR 1211.6), and the sensors are that means on most openers. Removing them takes away the part that stops the door when something is under it.

When to call

Call when the sensors are clean, lined up and showing steady lights and the door still will not close; when the door reverses off the floor and the manual's adjustment does not fix it; or when the door moves unevenly, sounds wrong or stops partway.

Updated 2026-09-30.